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    <title>center</title>
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    <div align="right">Last update : 20/12/2004</div>
    <p>
      <b>center</b> -   center</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>s=center(x)  </tt>
      </dd>
      <dd>
        <tt>s=center(x,'r') or s=center(x,1)  </tt>
      </dd>
      <dd>
        <tt>s=center(x,'c') or s=center(x,2)  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b></b>
        </tt>x: real or complex vector or matrix</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
     
    This function  computes <tt>
        <b>s</b>
      </tt>, the  centred version of
    the numerical matrix <tt>
        <b>x</b>
      </tt>.
     
    For  a  vector  or  a  matrix  <tt>
        <b>x</b>
      </tt>,  <tt>
        <b>s=center(x)</b>
      </tt>
    returns in  the <tt>
        <b>(i,j)</b>
      </tt> coefficient of  the matrix <tt>
        <b>s</b>
      </tt> 
    the  value <tt>
        <b>(x(i,j)-xbar)</b>
      </tt>, where  <tt>
        <b> xbar</b>
      </tt> is
    the mean of the values of the coefficients of <tt>
        <b>x</b>
      </tt>.
     
    <tt>
        <b>s=center(x,'r')</b>
      </tt>      (or,      equivalently,     
    <tt>
        <b>s=center(x,1)</b>
      </tt>) is  the rowwise center  reduction of the
    values of <tt>
        <b>x</b>
      </tt>.  It  returns in the entry <tt>
        <b> s(i,j)</b>
      </tt>
    the  value <tt>
        <b>(x(i,j)-xbarv(j))(j)</b>
      </tt>  with <tt>
        <b>xbarv(j)</b>
      </tt>
    the mean of the values of the <tt>
        <b>j</b>
      </tt> column.
     
    <tt>
        <b>s=center(x,'c')</b>
      </tt>      (or,      equivalently,     
    <tt>
        <b>s=center(x,2)</b>
      </tt>)  is the  columnwise center  reduction of
    the  values  of <tt>
        <b>x</b>
      </tt>.   It  returns  in  the entry  
    <tt>
        <b>s(i,j)</b>
      </tt>   the    value   <tt>
        <b>(x(i,j)-xbarh(i)))</b>
      </tt>   with
    <tt>
        <b>xbarh(i)</b>
      </tt> the mean of the values of the <tt>
        <b>i</b>
      </tt> row.</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

x=[0.2113249  0.0002211 0.6653811;
   0.7560439  0.3303271 0.6283918]
s=center(x)
s=center(x,'r')
s=center(x,'c')

 
  </pre>
    <h3>
      <font color="blue">See Also</font>
    </h3>
    <p>
      <a href="centrered.htm">
        <tt>
          <b>wcenter</b>
        </tt>
      </a>,&nbsp;&nbsp;</p>
    <h3>
      <font color="blue">Author</font>
    </h3>
    <p> Carlos Klimann</p>
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